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For FASTled, you will need to consult with the documentation, or possibly the FASTled web site. I vaguely recall that FASTled has its own method for DMA usage, but it can also uses the WS218Serial library or the...

FWIW, I've had other displays that worked better when I threw out the cheap jumper wires and went to better jumper wires and/or cut my own solid wire connections.
I've also had to throw out breadboards where over...

FWIW, if you order through digikey, the Samtec headers are sent by Samtec and not digikey. Unfortunately in doing the ordering, digikey does not specify what the shipping is.
I ordered headers from mouser, and they...

I do that all of the time. I generally put stacking headers on both the Teensy and the Audio Shield.
Though there are things to consider:
If you stack the audio board on top of the Teensy 4.0, you might not be...

Well in Teensy 4.x, you do have the option of using I2S2 instead of I2S1. The MCLK2 pin is 33 (back of the Teensy 4.1, underneath on the Teensy 4.0). So it doesn't interfere with the other standard 24 pins. The pins...

In theory it should work (assuming you have the right connection between SCL/SDA and the two machines).
Note, the resistor can be higher than 2.2k. Generally 4.7k is used for 5v systems. Generally, you want it...

I imagine you need 2 pull-up resistors on the i2c bus. A pull-up resistor is a resistor that is in parallel to the data path, and goes between the pin and 3.3v. You will need one resistor on the SCL line connecting to...

Good catch. I note that Mouser only has 34 on hand (at least in their Texas facility). Digikey has the Harwin Inc. M22-7140342 also. In both of those, the price is a little hefty ($1.16 for unit 1, plus of course...

Hmmm, you are right. I thought I had checked running the 4.0 version on 4.1 and the loader rejected it. I was able to load the Teensy 4.0 version on to the Teensy 4.1, and it gave me 1 megabyte file instead of the 7...

Yes, any cable where you have to puncture the cable to do the connection, is going to be wider on both sides. From the picture, it looks just like the Amazon part is just the other part where they just mated a fixed...

I tend to generally put stacking headers on my Teensys, such as this cut down to 24 pins:
http://www.dipmicro.com/store/HDR40X1FL
I was just idly assembling the components for attaching the ethernet to the 4.1....

Yes Circuit Python for Teensy 4.1 and 4.0 both are available:
Teensy 4.0: https://circuitpython.org/board/teensy40/
Teensy 4.1: https://circuitpython.org/board/teensy41/
There is a check in the Teensy loader...

Note, that Teensy 4.0/4.1 have different pinouts for the Audio shield than the Teensy 3.1/3.2/3.5/3.6 did. Thus you need revision D for Teensy 4.0/4.1 and revision C for the 3.x. So, you likely would need to change...

In doing the Teensy 4.0/4.1, Paul has mentioned several times that it is important that the wires to the audio shield be as short as possible. In addition, revision C of the audio shield added a 100 ohm resistor in the...

I don't know much about the Nextion, but I did look it up. It mentions that it supports the Raspberry Pi. Since the Pi similarly requires 3.3v processing, you might be able to see what things are needed to hook up a...

I don't really have a suggestion on the soldering iron.
But I found for soldering the psram chips to the beta/regular Teensy 4.1 and flash chips to the Teensy 4.1s, to the audio shields, and to SOIC8 adapters, that...

You should be able to. They do have normal pin numbers. Note, there two pairs of 8 pads. Two of the pads are are 3.3v and ground. Of the remaining pads, 5 of the pads are common between the two sets of pads (49, 50,...

PJRC.com resells the following cable that can be used:
https://www.pjrc.com/store/cable_usb_host_t36.html
Compared to the Teensy 3.6, the one thing that 4.1 doesn't have is solder pads under the Teensy to...

Could you give us a link to the exp-tech.de page with the psram?
FWIW, I put an order into Aliexpress.com on May 6th. Evidently it left China on May 21st, and I haven't seen any update to the tracking status since...

The 5 pins between the reset button and the micro-SD slot are the same pins in the back of the Teensy 4.0 (between outer row pins 13 and 12).
On the Teensy 4.1, including the two outer pins, these are:
Outer row...

It depends on exactly what you want to use in the prop shield.
With the exception of the back row of pins, all of the pins of the prop shields mate directly onto the 28 outer row pins on the Teensy LC, 3.0, 3.1, 3.2,...

Two things.
There are various bi-directional level shifters out there made to convert 3.3v to 5v for I2C. The pololu one is the one I typically have used in the past:
Pololu: https://www.pololu.com/product/2595...

Yes it can be done with the Teensy, though there are some things you may need to consider.
Since the Teensy 3.6 has 51 digital pins, you could just hook up each LED to a digital pin and a resistor. Note, you will...

Most pins, not all pins. It looks like on the Teensy 4.1, there are 15 pins that are not PWM capable (16, 17, 20, 21, 26, 27, 30, 31, 32, 34, 35, 38, 39, 40, and 41 in the outer row pins). In addition, there are only...

I did have a thought experiment, wondering besides USB/ethernet what would be the most sound outputs/inputs you could put on a Teensy 4.1, while still using the SPI ports, etc. My thought is:
I2S1 with 5 data...

One other possibility is that you could stick something on the I2C bus (MCP23008, MCP23017) that can bring out one or more pins to use as hardware reset pins. It isn't like that would be performance critical.
...

You didn't mention which Teensy you have. The simplest way is to look at the pinout card that came with your Teensy, or:
https://www.pjrc.com/teensy/pinout.html
And find the digital pins that don't have any...

Sorry about that. They changed around the quantity and such. Here is an updated link for the English speakers:
https://www.aliexpress.com/item/4000242457828.html?spm=a2g0s.12269583.0.0.73e055ceA37Za4
FWIW, I...

If we are listing DACs, we might want to list chips/boards that act as DACs, but have no ways to control them like we have with the SGTL5000. In particular, I've used boards with the MAX98357 and PCM5102 chips.

If you don't use the main SPI bus, using MQS (pins 10 and 12) might be a possibility. At least with the Teensy 4.1, you don't have to solder to the underneath pads to get access to the second SPI bus (assuming you want...

I'm just glancing at it right now. Note, all of these are suggestions. If it is not worth the return on investment, feel free to drop stuff.
I'm beginning to wonder it if would be better to have each of the major...

That last line is wrong for the 3.2. The Teensy 3.2 only has one DAC, so you should use AudioOutputAnalog instead of AudioOutputAnalogStereo. You can only use AudioOutputAnalogStereo on the Teensy 3.5 and 3.6 which...

IIRC, the first 2 serial ports on the Teensy 3.6 (Serial1 on 0/1, Serial2 on 9/10) have 8 byte hardware FIFO (first-in, first-out) hardware queues, so they are less likely to lose data if interrupts are turned off for a...

You don't need the master to have a separate uart to talk to each slave. Just have a protocol where the first byte/half-word/word or so of the message says which slaves to talk to. The slaves will ignore any message...

The library was created for the original Teensy 3.0. The Teensy 3.0 was originally released in October 2012. So yes, with the introduction of the Teensy 4, things have gotten messy. Some of the t3 libraries (like the...

I thought they were now working, but I did not know for certain, since I haven't used them.
Is there a simple setup that would allow using pins 14/15 on the Teensy 4.0/4.1 to play audio? My main interest is small...

The Teensy 4.0 and 4.1 does not have internal DAC's. Sound output options include:
Use the main digital I2S bus (which the revision D audio shield uses) -- either using the audio shield, or using another I2S output...

You want to use pin 19 (A5) to connect to SCL, and pin 18 (A4) to connect to SDA.
You may or may not need pull-up resistors on the I2C bus (it depends on whether the device already has it own pull-up resistors). I...

On Teensy 4.0/4.1, it isn't reset, but on/off. See my post above. On the Teensy 3.0, 3.5, and 3.6 it was reset. On the Teensy 3.1, 3.2, and LC it is the DAC (A14 or A12) that you can use to play mono sounds.
So to...

These are pins that are on the back or adjacent to the SD card on other Teensies. In particular, look at the back of the Teensy 4.0. Those 5 pins are the same on 4.1, except they are in a different position.
...

I suspect the 3.3v is the output of the 3.3v voltage regulator on the pcb. I.e. the PCM5102a runs at either 1.8v or 3.3v (max of 3.9v). So the pcb adds a voltage regulator to reduce the 5v down to 3.3v. They...

I've powered LCs with various things.
I do have some USB battery chargers that do not drop the power on low loads.
A lot of times, I'm powering WS2812B (neopixel) LEDs, so that is usually enough power to not have...

I was updating the unofficial wiki (https://github.com/TeensyUser/doc/wiki/Flash-Memory) on Flash and psram memory, and I added a section for psram sellers:
Pjrc.com: https://www.pjrc.com/store/psram.html
...

Disconnect the i2c device, and unplug the Teensy. Then turn on the Teensy then press the program button for exactly 15 seconds. It should put a basic blink program into the Teensy. Note, it takes some time erase the...

If you meaning running some variant of Linux on the T4.x, I doubt it. I would wonder if the T4's memory support is robust enough for what typical Linux wants in an OS, and the 2M flash memory in the T4.0 is a bit tight...

As I understand it, the SPI is not the same. I was asking a similar question before and the answer was it uses FlexSPI rather than the normal SPI (LPSPI). I believe the necessary pins are not brought out in the Teensy...

On the beta board I received, the ground pin between VIN and 3.3v was not connected. Similarly, the ground pin between pins 13 and 41 was not connected. The ground pin next to pin 0 and the ground pin in the middle...

To amplify what manitou said, you cannot use this in a pre-processor statement. It is a run-time variable that is set by the startup code to the size of the psram chips that are soldered on the board. The Teensy...

I thought KurtE's spreadsheet had a picture of the bottom part of the Teensy 4.1, but he right now only has a picture of the top. He does list the pads.
https://github.com/KurtE/TeensyDocuments.git/
I just got...

I believe the original Adafruit neopixels used the WS2812's, then moved to the WS2812B's, and now they generally use SK6812's.
Here are two pages that I've seen that compare them:
WS2812 vs. WS2812B:...

Here is a site with general information about cache memory in general that I found with a google search:
https://searchstorage.techtarget.com/definition/cache-memory
The Teensy 4.0 page has a better explanation...

Vbat is the pin you connect the positive lead from a coin battery (you connect the negative lead to ground). With the coin battery, the real time clock will be powered when there is no power to the main Teensy.
In...

Yes, the _r stuff is for re-entrant code, but I didn't know if we could use the framework for separate heaps. I would imagine however, when the dual-core Teensy comes out that Paul has talked about, we may need to...

Rather than continue the discussions about adding a malloc layer for the psram memory on the Teensy 4.1 beta thread, it is probably better to open a new thread about it.
Here are some open source malloc...

Great! It will be good to get the official documentation updated. Besides adding 4.0 and 4.1 stuff, it may be time to more clearly segregate the Teensy 2.x information. I assume, you have plenty of things you know...

It is similar to functions. An extern variable declared weak is normally treated as an external reference. I.e. the definition of the variable must be in some other module.
However, if the linker doesn't find the...

Yep, I expect SPIFFS and eFlash to be externally set up. It would be nice if the library shipped with the Teensydunio 1.52, but if it doesn't, I can use the external library.
I have a horrid mix of library files...

Will we have the SPIFFS stuff in 1.52 or will it be still a separate library?
I am wondering for 1.53, whether we need a class that sits between the audio readers (i.e. RAW, WAV, etc.) and the actual filesystem (SD,...

There are various videos on how to solder SMD. I tend to do it my own way.
Get the smallest solder wire you can find. The normal kester solder wire that I use is 0.031" thick. For the two memory chips, I was using...

The audio shield revision D (i.e. same as Teensy 4.0) can be used.
The 28 exterior pins for the 4.0 map exactly to to the first 28 pins (14 on each side) on the Teensy 4.1. Like the Teensy 3.5/3.6 in comparison to...

Ok, I got my PSRAM chip in the mail, and just soldered it in. I changed the flashtest7FL to init the PSRAM (which formats a lot quicker than flash). It seems to work, except it reports the wrong ID.
...

To add a little nuance to defragster's post.
When you select the Teensy 3.5, there is a drop down menu giving the various speeds. On the Teensy 3.5, the options are:
Normal speeds: 120MHz, 96MHz, 72MHz, 48MHz,...

FWIW, the Circuit Python on Teensy 4.0 provides a USB disk interface using the T4's flash memory. It provides a 1M filesystem. Paul did recently send a 4.1 beta to the Circuit Python developer.
Ultimately, it would...

Basic Information

About MichaelMeissner

Biography:

I am a computer programmer that has worked on compilers for over 33 years. I have been working on the GNU GCC compiler for over 20. Outside of work, I tend to be known for my steampunk camera (see http://www.steampunkmike.org for more details).